HARNCHOOWONG, A.; SOMBOONKULAVUDI, C. A Ring of Pythagorean Triples over Quadratic Fields. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 66, n. 1, p. 135–139, 2014. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/2117. Acesso em: 5 dec. 2025.